The plane was carrying four pallets of heavy equipment, said Maj Lowe, who described the flight as a standard shipment into Bagram Air Field in eastern Afghanistan. Maj Lowe declined to name the company that owns the plane or the aircraft's point of departure until relatives of the crew were notified.

The plane hit a mountain peak late on Tuesday night, said Sayed Aleem Agha, the top official in Sayagred district of Parwan province, north of Kabul.

He said he fears that crew members were killed, but that rescue workers had not yet arrived at the crash site.

"I saw a huge fire as a result of the crash," he said. "My guess is that it was a big cargo plane because the fire lasted for a long time."

Abdul Shakoor, a police official in neighbouring Shinwari district, also said that a cargo plane had crashed into the mountain.

British Major Tim James, a spokesman for the coalition in Afghanistan, said the plane crashed about 12,500 feet up the mountain. There was no insurgent activity in the area at the time of the crash, he said.